The Intellirod LOADPRO™ sensor is an intra-operative titanium and ceramic, single use, disposable, strain sensing device, which includes hermetically sealed, micro electromechanical systems (MEMS) and radio-frequency identification (RFID) technology to enable measurement of intra-operative rod strain values. The transponder attaches to any commercially available 5.5mm diameter CoCr or Ti Alloy rod commonly used for posterior pedicle fixation systems. The transponder is used only to acquire rod strain values and a unique device identification code, which is obtained by a hand-held reader, providing real-time, objective measurement of the mechanical rod strain.